The Open Publication Distribution System (OPDS) Catalog format is a syndication format for electronic publications based on Atom and HTTP. OPDS Catalogs enable the aggregation, distribution, discovery, and acquisition of electronic publications. OPDS Catalogs use existing or emergent open standards and conventions, with a priority on simplicity.[1]

<?xmlversion="1.0"encoding="UTF-8"?><feedxmlns="http://www.w3.org/2005/Atom"xmlns:dc="http://purl.org/dc/terms/"xmlns:opds="http://opds-spec.org/2010/catalog"><id>urn:uuid:433a5d6a-0b8c-4933-af65-4ca4f02763eb</id><linkrel="related"href="/opds-catalogs/vampire.farming.xml"type="application/atom+xml;profile=opds-catalog;kind=acquisition"/><linkrel="self"href="/opds-catalogs/unpopular.xml"type="application/atom+xml;profile=opds-catalog;kind=acquisition"/><linkrel="start"href="/opds-catalogs/root.xml"type="application/atom+xml;profile=opds-catalog;kind=navigation"/><linkrel="up"href="/opds-catalogs/root.xml"type="application/atom+xml;profile=opds-catalog;kind=navigation"/><title>Unpopular Publications</title><updated>2010-01-10T10:01:11Z</updated><author><name>Spec Writer</name><uri>http://opds-spec.org</uri></author><entry><title>Bob, Son of Bob</title><id>urn:uuid:6409a00b-7bf2-405e-826c-3fdff0fd0734</id><updated>2010-01-10T10:01:11Z</updated><author><name>Bob the Recursive</name><uri>http://opds-spec.org/authors/1285</uri></author><dc:language>en</dc:language><dc:issued>1917</dc:issued><categoryscheme="http://www.bisg.org/standards/bisac_subject/index.html"term="FIC020000"label="FICTION / Men's Adventure"/><summary>The story of the son of the Bob and the gallant part he played in
the lives of a man and a woman.</summary><linkrel="http://opds-spec.org/image"href="/covers/4561.lrg.png"type="image/png"/><linkrel="http://opds-spec.org/image/thumbnail"href="/covers/4561.thmb.gif"type="image/gif"/><linkrel="alternate"href="/opds-catalogs/entries/4571.complete.xml"type="application/atom+xml;type=entry;profile=opds-catalog"title="Complete Catalog Entry for Bob, Son of Bob"/><linkrel="http://opds-spec.org/acquisition"href="/content/free/4561.epub"type="application/epub+zip"/><linkrel="http://opds-spec.org/acquisition"href="/content/free/4561.mobi"type="application/x-mobipocket-ebook"/></entry><entry><title>Modern Online Philately</title><id>urn:uuid:7b595b0c-e15c-4755-bf9a-b7019f5c1dab</id><author><name>Stampy McGee</name><uri>http://opds-spec.org/authors/21285</uri></author><author><name>Alice McGee</name><uri>http://opds-spec.org/authors/21284</uri></author><author><name>Harold McGee</name><uri>http://opds-spec.org/authors/21283</uri></author><updated>2010-01-10T10:01:10Z</updated><rights>Copyright (c) 2009, Stampy McGee</rights><dc:identifier>urn:isbn:978029536341X</dc:identifier><dc:publisher>StampMeOnline, Inc.</dc:publisher><dc:language>en</dc:language><dc:issued>2009-10-01</dc:issued><contenttype="text">The definitive reference for the web-curious
philatelist.</content><linkrel="http://opds-spec.org/image"href="/covers/11241.lrg.jpg"type="image/jpeg"/><linkrel="http://opds-spec.org/acquisition/buy"href="/content/buy/11241.epub"type="application/epub+zip"><opds:pricecurrencycode="USD">18.99</opds:price><opds:pricecurrencycode="GBP">11.99</opds:price></link></entry></feed>